scholarly journals The Influence of pH and Temperature on the Stability ofN-[(Piperidine)methylene]daunorubicin Hydrochloride and a Comparison of the Stability of Daunorubicin and Its Four New Amidine Derivatives in Aqueous Solutions

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mikołaj Piekarski ◽  
Agnieszka Dołhań ◽  
Judyta Cielecka-Piontek ◽  
Przemysław Zalewski ◽  
Witold Kycler ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Hplc Method ◽  
Base Catalysis ◽  
Spontaneous Hydrolysis ◽  
Influence Of Water ◽  
Enthalpy And Entropy ◽  
The Stability ◽  
Protonated Molecules ◽  
Influence Of Ph ◽  
Hydrolysis Of

The influence of pH and temperature on the stability ofN-[(piperidine)methylene]daunorubicin hydrochloride (PPD) was investigated. Degradation was studied using an HPLC method. Specific acid-base catalysis of PPD involves hydrolysis of protonated molecules of PPD catalyzed by hydrogen ions and spontaneous hydrolysis under the influence of water zwitterions, unprotonated molecules, and monoanions of PPD. The thermodynamic parameters of these reactions, energy, enthalpy, and entropy, were calculated. Also, the stability of daunorubicin and its new amidine derivatives (piperidine, morpholine, pyrrolidine, and hexahydroazepin-1-yl) in aqueous solutions was compared and discussed.

scholarly journals The influence of pH and temperature on the stability of flutamide. An HPLC investigation and identification of the degradation product by EI+-MS

RSC Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 3206-3214 ◽  
Author(s):  
R. N. El-Shaheny ◽  
K. Yamada
Keyword(s):  
Degradation Product ◽  
Degradation Kinetics ◽  
Hplc Method ◽  
Profile Curve ◽  
Arrhenius Plots ◽  
Stability Indicating ◽  
The Stability ◽  
Rate Profile ◽  
Influence Of Ph

Stability of flutamide was investigated using validated stability-indicating HPLC method. Degradation kinetics, Arrhenius plots, and pH-rate profile curve were explored.

The influence of pH on the stability of antazoline: kinetic analysis

RSC Advances ◽  
2015 ◽  
Vol 5 (83) ◽  
pp. 68179-68186 ◽  
Author(s):  
Kārlis Bērziņš ◽  
Ilze Grante ◽  
Ilva Nakurte ◽  
Andris Actiņš
Keyword(s):  
Aqueous Solutions ◽  
Kinetic Analysis ◽  
The Stability ◽  
Influence Of Ph

Degradation of the drug antazoline was studied in aqueous solutions by means of pH-rate profiling (pH 0–7.4).

Influence of pH and cationic surfactant on stability and interfacial properties of algerian bitumen emulsion

2016 ◽  
Vol 70 (9) ◽  
Author(s):  
Abdelkader Benderrag ◽  
Mortada Daaou ◽  
Boumedienne Bounaceur ◽  
Boumedienne Haddou
Keyword(s):  
Interfacial Tension ◽  
Cationic Surfactant ◽  
Interfacial Properties ◽  
Aqueous Emulsion ◽  
Bitumen Emulsion ◽  
Influence Of Water ◽  
Water Ph ◽  
The Stability ◽  
Influence Of Ph ◽  
Test Bottle

AbstractThe influence of water pH and cationic surfactant content on the interfacial properties and stability of an Algerian bitumen aqueous emulsion were investigated. While the stability was quantified by both the test-bottle method and size distribution measurements, the interfacial properties of the water–bitumen interface were assessed using interfacial tension measurements. Optical microscopy was also used to visualise the dispersed water droplets in the oil phase. The results showed that addition of the cationic surfactant at a concentration of 25 mmol L

scholarly journals Studying the kinetics of salicin hydrolysis in an acidic environment

2020 ◽  
Author(s):  
A. B. Sabutova
Keyword(s):  
Aqueous Solutions ◽  
Hplc Method ◽  
Acidic Environment ◽  
Strong Acids ◽  
Kinetics Of ◽  
Hydrolysis Of

The work is devoted to the study of the kinetics of the hydrolysis of salicin in aqueous solutions. To determine salicin in the objects of study, the HPLC method was used. During the study, it was found that the hydrolysis of salicin occurs only in aqueous solutions of strong acids.

scholarly journals Antitumour Metallocenes: Effect of DMSO on the Stability of Cp2TiX2 and Implications for Anticancer Activity

1998 ◽  
Vol 5 (4) ◽  
pp. 207-215 ◽  
Author(s):  
George Mokdsi ◽  
Margaret M. Harding
Keyword(s):  
Nmr Spectroscopy ◽  
Aqueous Solutions ◽  
Anticancer Activity ◽  
Active Species ◽  
Aromatic Rings ◽  
Cyclopentadienyl Ligands ◽  
Rate Of Hydrolysis ◽  
The Stability ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of

The rate of hydrolysis of the aromatic rings of Cp2TiX2 [X = CI 1, O2CCCl3  8 and O2CCH2NH3Cl  13], in aqueous solutions, 10%DMSO and 100% DMSO have been studied by H1NMR spectroscopy. Rapid hydrolysis of both the carboxylate and cyclopentadienyl ligands in Cp2TiX2[X = O2CCCl3,O2CCH2NH3Cl] occurs in DMSO to give biologically inactive species. The rate of these reactions are concentration dependent as dilution of these samples with saline or water to give the therapeutic conditions of 10%DMSO/90%H2O slows the hydrolysis chemistry. In contrast, samples of Cp2TiX2 [X = CI 1, O2CCH2NH3Cl  13], dissolved in water give solutions containing the presumed antitumour active species in which the halide or glycine ligands have been hydrolysed but the Cp rings remain metal bound.

scholarly journals Influence of pH, temperature, and light on the stability of melatonin in aqueous solutions and fruit juices

Heliyon ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. e03648 ◽  
Author(s):  
Thorung Pranil ◽  
Anuchita Moongngarm ◽  
Patiwit Loypimai
Keyword(s):  
Aqueous Solutions ◽  
Fruit Juices ◽  
The Stability ◽  
Influence Of Ph

Solvolysis of some 1-(8α-ergolinyl)-3,3-diethylureas and their salts

1987 ◽  
Vol 52 (5) ◽  
pp. 1331-1339 ◽  
Author(s):  
Antonín Černý ◽  
Jan Beneš ◽  
Jaroslav Vachek ◽  
Milan Pešák ◽  
Josef Stuchlík ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Main Product ◽  
Ethanolic Solution ◽  
Decomposition Products ◽  
Solubility In Water ◽  
Long Term Storage ◽  
The Stability ◽  
Hydrolysis Of ◽  
Term Storage

Nine salts of 1-(8α-ergolinyl)-3,3-diethylurea (II) were prepared and their solubility in water and the stability of the aqueous solutions at 60 and 100 °C were studied. The main product of hydrolysis is 6-methyl-8α-aminoergoline IV. The urethan VII is formed in the ethanolic solution. Both decomposition products are also formed under long-term storage at +5 °C. The course of hydrolysis of N-propyl homologue III is similar. The decomposition of 9,10-didehydro derivative I is much slower under the conditions used.

Hydrolysis of ethylenediphosphinetetraacetate anions

1983 ◽  
Vol 48 (6) ◽  
pp. 1552-1557
Author(s):  
Jana Podlahová ◽  
Jaroslav Podlaha
Keyword(s):  
Nmr Spectroscopy ◽  
Aqueous Solutions ◽  
Stability Of Solutions ◽  
Laboratory Temperature ◽  
H Nmr ◽  
Isolation And Characterization ◽  
Acid And Base ◽  
The Stability ◽  
Hydrolysis Of

The anions of ethylenediphosphinetetraacetic acid are hydrolyzed in aqueous solutions at 80 °C in the two following reactions: ((OOCCH2)2PCH2CH2P(CH2COO)2)4- → (OOCCH2(O)HPCH2CH2PH(O)CH2COO)2- → (O(O)HPCH2CH2PH(O)O)2-. Both reactions are acid and base catalyzed so that, at pH < 12, the first reaction is much faster than the second. The reaction course was studied by 1H NMR spectroscopy and by isolation and characterization of the products. The effect of both reactions on the stability of solutions of ethylenediphosphinetetraacetic acid and their salts is negligible at laboratory temperature.

On the Structure of Lead(II) Complexes in Aqueous Solutions. I. Trinuclear Clusters

1995 ◽  
Vol 60 (4) ◽  
pp. 527-536 ◽  
Author(s):  
Martin Breza ◽  
Alena Manová
Keyword(s):  
Quantum Chemistry ◽  
Aqueous Solutions ◽  
Electronic Structures ◽  
Mndo Method ◽  
Model Systems ◽  
Trinuclear Clusters ◽  
The Stability ◽  
Semiempirical Mndo

Using semiempirical MNDO method of quantum chemistry the optimal geometries and corresponding electronic structures of [Pb3(OH)n]6-n model systems as well as of their hydrated [Pb3(OH)n(H2O)8-n]6-n analogues (n = 4, 5) are investigated. The most stable trinuclear lead(II) complexes present in aqueous solutions correspond to cyclo-(μ3-OH)(μ2-OH)3Pb32+, Pb(μ-OH)2Pb(μ-OH)2Pb2+, cyclo-(μ3-OH)2(μ2-OH)3Pb3+, Pb(OH)(μ-OH)2Pb(μ-OH)Pb(OH)+ and Pb(OH)(μ-OH)2Pb(μ-OH)2Pb+ systems. The key role of OH bridges (by vanishing direct Pb-Pb bonds) on the stability of individual isomers is discussed.

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